The soul of the king, the four winners are immortal. Immortals are actually Prometheans with thinking ability after acquiring souls, and then further evolved into flesh-and-blood humans (giants) and human subspecies dwarves (humans in our concept). Later Baijiao studied this secret, reversed this process with secret methods, and artificially created undead, with the purpose of completing the task with the help of the characteristics of undead (as long as it does not become a thorough Promethean, the undead with spiritual wisdom is almost immortal, and no matter how it is killed, it can be magically reborn near the fire, provided, of course, that the fire still exists. If the initial fire goes out, a Promethean cannot exist. It is unrealistic for ordinary people to venture to Ladland to complete the task. We have all experienced unrealistic methods in the game. Ordinary people die once and die completely once.